Stoker



latented Wlan 23,

attente spontan .lames Gunnell Malone, 'liottenville, Staten Island, N. Y.

Application December 27, 1933, Serial No. 704,211

20 Claims. (Cl. 11d-45) 'I'his application is a continuation-in-part of my application Serial No. 602,955 led April 4,

i932 and entitled Stoker.

This invention relates to new and useful improvements in stokers for furnaces and in gas producers and the like.

The invention has for an object the construction of a stoker which is characterized by a-grate, means for moving the grate to cause a crushing 1o action in conjunction with an opposed surface such as the wall of a furnace, and means for simultaneously providing a continuous motion of the fuel bed to prevent clinkering.

Furthermore, as another object of this invention it is proposed to provide an annular ash conveying member with air passages for air, beneath said grate to cool the grate and to convey ashes.

Another object of this invention is to provide 2g air seals within the' mechanism to prevent -air circulation up through the ash discharge space, and to allow ashes to fall freelywithout the interference rof an adverse current of air. Furthermore, it is proposed to arrange the seals so as to prevent air from ilowing up through the ash space and around the periphery of the grate, and force Ythe air to flow up through parts around the l ub oi an eccentric of the device. thus emciently cooling said parts and at the same time blowing 3g) ash away from the eccentric bearing surface.

A still further object of this invention is the construction of adevice of the class described which is of simple durable construction, dependable in use and efficient in operation and which g5 can be manufactured and sold at a reasonable c cost.

, For further comprehension of the invention,

and of the objects and advantages thereof, reference will be had to the following description and .10 accompanying drawings, and to the appended claims in which the various novel features of the invention are more vparticularly set forth. VIn the accompanying drawings forming a material part of this disclosure:- 4 5 Fig. 1 is a plan view of a device constructed according to this invention.

Fig. 2 is a. fragmentary sectional view taken on the line 2 2 of Fig. 1.

Fig. 3 is a fragmentary Fig. 4 is a fragmentary sectional view taken on the line 4 4 of Fig. l..

Fig. 5 is a fragmentary sectional view taken on the line 5-5 of Fig. 4. 55 Fig. 6 is a fragmentary view similar to a portion l horizontal sectional .30 view taken on the line 3 3 of Fig. 2.

of Fig. 2 but representing a section taken on the line 6 6 of Fig. 1.

Fig. 7 is a plan view of the combination annular air distributor and ash conveyor used in the de Y vice, illustrated per se, and also shows the actu- 5 ating eccentric.

Fig. 8 is a vertical sectional view of Fig. 7 taken on the line 8-8 of Fig. 7.

'Ihe structure, according to this invention, has a body l0 for placement in a furnace,'indicated 1o generally on the drawings by reference numeral Il. A filler l2 is shown interposed between the furnace and the body l0 providing a shelf upon which the ash may assume an inclined shape, indicated by reference numeraly i3. 'I'his shelf l2 15 and ash deposit i3 are especially provided to act as a safety cushion for tramp iron, etc. The top of, the fuel bed is indicated by reference numeral it. The top of the body I0 is open and a fuel feed tube i5 extends through the body and has a 20 vertical portion at the center of the body and a horizontal portion passing through the side of the body to the hopper as clearly shown in Fig. 4.' The top of the vertical portion of the fuel feed tube l5 has a spherical zone seat it. 25

.An annular ash conveying member with air passages has an annular portion Il and is rotatively mounted on a hub portion i8 of the vertical portion of the fuel feed tube l5. The

annular ash conveying member with air passages 3o has an eccentric i9, eccentric on its outer face, air passages 2li, and an ash supporting surface 2i. The annular portion il is coaxially mounted with respect to the feed tube l5 and is supported in. spaced relation thereto by means of a plurality oi radially extended arms or spokes i9 rigidly 'connected to the portion il and the eccentric it so as to form openings between these parts; The eccentric outer iace of the eccentric lil is oil-cylindrical shape but has its axis arranged at i0 an inclination as clearly illustrated in Figs. 6,

7 and 8.l More particularly the axis of the cylindrical outer face of the eccentric I9 crosses the axis of the central opening Ain the eccentric at a point W which corresponds (see Fig. 6) with 45 the common center of the spherical zones l and 25 and 2li. To better understand this construction, the line X in Fig. 7, appearing in this gure as a point because seen in end elevation, represents the center of the opening in the eccentric ill, which corresponds with the line X in' Fig. 3 also representing the axis of the feed tube i5. The point Yin Fig. 7 corresponds with the point Y in Fig. 8 and the distance between X and Y represents the eccentricity of the outer face of veying member with vlindrical surface iia during Yfar as rotation is concerned has the eccentric at the top of the eccentric. The line Z in Figs. 6 and 8 represents-the axis ,-oi the cylindrical outer face of the eccentric i9, said line Z extending through the point Y and intersecting the line X at the point W. The point W corresponds with the common center of curvature of the spherical zones i6 and 25 and 2,9. A baille portion 22 projects from the annular ash conair passages and serves to effectively separate the ash conveying portion from the air passage portion, the air passing therethrough acting to eiectively cool the eccentric bearing surface.

A grate 23 is located above the annular ash conveying member and has a central fuel entrance passage 215i formed by a hub having a spherical zone portion 25 at its bottom engag ing upon the spherical zone seat it and an outer portion 26 encircling the eccentric is. The spherical zone portions 'is and 25 constitute a bearing for supporting the grate 23. The inner face of the portion 26 is cylindrical and has its axis corresponding with the axis of the grate and engages the outer eccentric face of the eccentric iii. The sectional view illustrated in Fig. 2 is taken upcnythe neutral plane 2-2 of Fig. 3 and for this reason the contacting faces of the eccentric i@ and the portion 26 are in the vertical and furthermore for this reason the thickness of the walls of the eccentric i9 are identical. 'in Fig. 6 the section is taken upon a plane represented by the line 5 6 of Fig. 3, which is plane giving the maximum tilt of the grate due to the eccentric i9. Rotation of the eccentric i9 causes the grate to move in a wcbbling gyratory path and the grate itself is supported on spherical zones it and 25 to accommodate this wobbling gyratorynniotion. The grate itself will not rotate but the high and low points respectively will progress or revolve continuously around during the gyratory motion. Expressed in dif ferent words the grate while standing still as centric wobble which moves around in a circle. The grate 23 has a pluralityfof air passage openings 21 extending from the top to the bottom and arranged over the conveying surface 2i and constitutes the re bed area. The portion of the grate formed with the openings 2'! is at an inclination downwards so as to form substantially a frusto-conical surface, the purpose being to insure the proper passage of the ash as hereinafter fully described, and also so oppose the innerv wall il of the furnace il. During the wobbling gyratory action of the grate the material on the grate will be crushed against thel wall il by portions thereof moving towards the wail iin. This may be better understood by examining Fig. 6, in which figure the truste-conical surface is confined between the letters AB and CD. If the lines AB and CD were continued until they niet in. a point, a cone would be formed. Consequently, the annular surface AB and CD is frusto-conical. Material on the grate caught in between this frustoconical surface and the cy the gyrating of the grat/e, will be crushed. For example, one line of crushing will exist along the line EF. On this line several lumps of solid fuel such as coal or colse are shown extended along the line and indi cated by reference numerals i3, The reason crushing takes place is that while this particular .portion of the grate moves upwards, it also moves closer to the wall. In other words, the crushing is due to the fact that the grate has a particular a continuous ecaotasoc gyratory motion. This gyratory motion may dened as the motion which the frusturn of a cone AB and CD would describe if the axial center line Z of the frustum of the cone were re volved on an imaginary conical surface having as its exis the line X. and as its apex the point W. In order to obtain the desired motion it is necessary that the apex W of the imaginary conical surface be on the same side of the has@ of the frustuni of the cone AB and CD as that of the apex of a cone having the frustum and CD. When so constructed the grate will prom gressively tilt so that when a side portion thereof is moved upwards it will Simultaneously be moved towards the wail i la. Crushing then takes piace. On the downward motion this portion of the grate will simultaneously move away from the wall it so that the crushed material will settle down and be in position to be crushed again during the next cycle of operation of the grate.

This particular gyratory motion must be disn tinguished from the gyratory motion in a grate having a truste-conical portion and CD is mounted upon the top end of a gyratory shaft. In this latter case the axis of the grate would revolve on an imaginary conical surface the apex o which is on the opposite side of the base of the truste-conical shape. 'When thus arranged crushing will not taire place because then, if a portion of the grate moves upwards, it simultaneously moves away from the opposed wall. Subsequently, when that portion moves downwards it moves towards the wall. Screen material 28 for preventing small particles of iuei from falling through the grate may be attached on the grate 23 over the passages 2li.

A spherical zone shaped ash passage 2Q exists between the periphery of the grate 23 and the top opening in the body it. The adjacent surfaces of thegrate (the edge thereof), and the top opening in the body it) are substantially spherical zones having their centers of curvature W coinciding with the center of curvature W of the spherical zone seat I6 and the spherical zone surface 25. This arrangement serves to form an ash passage 29 of constant cross section between the body i@ and .the grate irrespective of the position of gyration of the grate. will be clearly understood by considering Figs. 2 and 6 and imagining the grate tilting first in one direction and then in the other on the spherical zones it and 25 and then bearing in mind that the adjacent spherical zone surfaces of the body i@ and the grate; that is, the walls of the .spherical zone shaped passage 29, are on concentric circles with the centers coinciding with the centers of the spherical zones it and 25, and furthermore that motion takes place about these coinciding centers as an imaginary pivot point. This same condition holds true in all central vertical sections which may be cut through the axis of the grate. Qne advantage of maintaining the passage 29 constant between the grate and the body is that foreign matter such as tramp iron, slate, rock and other articles cannot become wedged in the passage 29 be tween the body and the grate and cause stresses and perhaps breaking of the device. If this pas' sage 29 between the body and the grate varied during the gyratory motion it can easily be seen that if a foreign piece of matter were wedged in this opening the gyratory motion could not continue and if forced to continue something xnust break,l either the foreign matter, or, if the foreign matter is iron that would not break, then a part of the Stoker. Another important advantage of keeping the passage 29 between the body and the grate constant during the gyratory motion is that then this passage may be very small to allow the passage of ash only. If this passage 2@ changed during the gyratory motion there would be a time when it is large and a time when it is small and consequently when the passage is large, large pass through. Another advantage is`that the eccentricity of the grate motion is not limited by f of the portion i1 of the annular ash conveying member and the body ill, and particularly comprises flanges 3i and 32 projecting from the portion i1 and from the body it and extending towards each other so as to form the space 3c which becomes lled with ashes or winch may be lled with other material to produce the air seal. A fuel feed is associated with the fuel feed tube i5 and comprises, particularly, a fuel feed tube l5 from a fuel supply such as the hopper 3E. The fuel feed tube i5 is rmly supported within the body i@ by reason of a support bar 35 attached upon the side of the fuel feed tube and attached on the body lil. The screw 33 terminates at one end at the portion where the fuel feed tube l5 turns upwards. They hopper 34 has a gate 31 normally extended vover a side opening 38 in the hopper so as to form a part of the hopper Wall and adapted to be moved into a position indicated by the dot ancldash lines 39 to close the passage through the hopper and simultaneously form an opening in the side of the hopper so that the interior is exposed. More particularly, a mechanism is provided for moving the gate as desired and comprises a pair of pins do projecting from the sides of the gate and engagingin vertical grooves di formed in the hopper 34. A lug d2 projects from the gate 31 and is pivotally engaged by a lever d3 xed at its lower end on a horizontal control rod di and to assume a position indicated by the dot and dash lines t3 which is the closed position. The shaft d6 of the screw 33 extends through the hopper and is connected with a drive as hereinafter further described.`

A means is provided for revolving the annular ash conveyingmember and comprises a circular flange d1 projecting from the bottom of the portion i1 of the annular ash conveying member and formed with bevel teeth d8 meshing with bevel teeth upon a ring gear 49 rotative on the horizontal portion of the fuel feed tube i5. The ring gear d@ is also provided with spur teeth 50 meshing with a pinion 5i upon a drive shaft 52 projecting from the body i0.

An ash discharge is arranged in conjunction with'the annular ash conveying member, see Fig. 2, and comprises particularly a scraper element 53 projecting from the inner Wall of the casing Ill and extending in the space above the ash conveying surface 2i. This scraper is adapted to deflect the ash from the conveying surface 2l through an opening 54 in the side of the body it. An ash cover 55 is attached upon the side of the casing l@ over the opening 5d to direct the ash downwards to anlash container 56. An ash conveyor is associated with the ash discharge and includes an air seal. More particularly, a transfer casting 51 is attached upon the ash container 56 and has a horizontal portion 58, an inclined portion 59, and a vertical portion 5d. A horizontal ash screw di is arranged upon the jection 38 from the casing 1I.

. er shaft 52 'and extends through the horiaontai portion 53 of the transfer casting. A bevel gear 62 is attached upon the shaft 52 outside of the transfer casting and meshes with another bevel gear G3 on a shaft @il extended through the vern tical portion of the transfer casting. The por-a tion is not truly vertical but really at an inclination to the vertical as may be seen from inspecting Fig. 1 so that the ash is conveyed to one side for connection with a suitable discharge. A substantially vertical ash screw 65 is connected with the shaft 64, to force the ash 4upwards. Particular attention is called to the inclined portionA 5g of the transfer casting 51 which portion necessarily must be packed withashes by the screw 6l before the screw 65 receives the ashes to convey them away. Consequently, the portion 59 constitutes an air seal. Furthermore, the vertical screw 65 need not be a close nt in the vertical portion of the transfer casting in that the seal portion 59 holds the ashes from falling down.

A means is provided for causing an air 'current beneath the annular ash conveying mem.;I ber and comprises 61 in connection with the shaft of a drive motor 68. A duct 69 connects with the fan 66 and discharges into the body NJ. The motor 68 is also utilized to operate the drive unit 10. This drive unit comprises a casing 1i in which the mechanism of the unit is housed. More particularly, a Worm pinion 12 is mounted upon the shaft 61 and is in mesh with a worm wheel 13 free upon the shaft Y 1i. A lever'lt is also free upon the shaft 46 and has a head end' 15 and a tail end 16. The head end 15 is -formed with openings through which a small diameter rod 11 passes so that said head end i5 is movably supported upon said rod 11 which is in turn supported on the casing 1I. An adjustment screw 18 through the casing 1| is a fan 66 driven -by ashaft t6 which extends through the casing adapted to engage in the path of motion of the so as to limit 'its travel as desired. roller 19 is mounted upon the side of the worm wheel 13 and engages in an opening B0 in the lever 1d. Shaft t6 passes through said opening 90. A pawl 83 mounted on the casing 1l acts against the ratchet wheely.82 limiting rotation in one direction only. A sprocket 85 is mounted upon the shaft 46 and is engaged by a chain 86 extending over another sprocket 81 mounted upon the shaft 52.

The operation of the drive unit will be understood by considering that as the motor 68 operates the drive shaft 61 will rotate. This rota-I tion is transmitted by the worm pinion 12 to the worm wheel 13. The eccentric 19 on the worm wheel 13 will cause the lever 1d to pe riodlcally oscillate back and forth. The adjust-A ing screw 18 may-be adjusted to limit the oscillation o1 the head end of the lever 14 to cause the tail end to move in an inverse ratio, that is, when the head end is restricted the tail end will move further. The head end of the lever 1t may move between the screw 16 and a pro- Thus the pawi 8l will cause turning of the ratchet wheel 82. one, two, etc., number of teeth upon each oscillation depending upon the adjustment of the head end 15 An eccentric screw 18. A mechanism not shown onjthe draw-` iced tube fuel is discharged irom fuel iced tube it upon the grate 253. The air supply for the burning fuel may be traced from the blower bij through the duct tti into the lower portion ot l tion of theshat 52 causes the turning o the pinion iii, the ring gear t@ and the air distributor and ash conveyor l'i. As the member il turns, the eccentric i9 will cause the grate 2S to rnove correspondingly and ride upon the spherical zone surface iii so as to have a continuous wobbling gyratory crushing action in conjunction with the inner side i of the furnace and a fuel bed. fi

feature of the crushing action is that all portions of the grate move towards the wall il toI crush and away from the wall iia to cause additional material toventer between the wall ila and the grate. Ashes from the re will fall through the passage 2d and some ashes mayv also iall through i openings 2l in grate 23 upon the conveying surface 2i. These ashes will be forced ofi surface 2i by the scraper 53 as the air distributor and conveyor ii revolves. These ashes will pass through the opening 5d and down the ash hopper itil. 'irom there the ashes will be forced up tl'irough the inclined portion e9 oi the transfer casting to the screw b5 and thence to the discharge not shown on the drawings. The ash accumulation within the portion $9 constitutes an air seal. Another air seal exists between the portion of the annular ash conveying member and the body iii, namely, air seal 3b so as to cause the draft caused by the fan tt to yonly pass through the passages 2t. The baiie iiange 222 directs the air beneath the grate 23 from which it will ow through the passages 2l. It should be noted that none of the ashes or fuel can possibly fait inside oi the baiie 22 and thus to the bottom of the body i@ but must fall upon the conveying surface iii. The action of the grate 23 will be to breaia up clinlrering oi the ash and give a continuous motion to the fuel bed thereby eliminating formation oi holes in the fuel bed and impingement oi `air current and so preventing clinkering and thus insuring the proper combustion in the stolier and a continuous shaking or working down and elimination o the ash.

While l have illustrated and described my invention with some degree o particularity, I realize that in practice various alterations therein may be made.' i1 therefore reserve the right and privilege oi changing the forni ofthe details oi construction or otherwise altering the arrangement of the correlated parts except as limited by the scope oi the appended claims.

Having thus described my claim as new, and desire toA secure by United States Letters Patent is:-

.In a Stoker, .a vertical member having a spherical seat, a grate having a complementary spherical seat coacting with said rst-named spherical seat for supporting said grate, and means coacting with said grate for circumferentially progressively tilting said grate on said spherical seat.

2. in a Stoker, l seat, grate having a complementary spherical seat coacting with said first-named spherical seat for supporting said grate, and means coacting said grate for circumferentially progressiveinvention what iK a member having a spiflericalv acre-ece "l ation oi the fuel feed screw and carries iuei` Ifrom the hopper Sli through the iuei ly tilting said. grate on said spherical seat, coinprising an eccentric rotative on said member and ournalied in, a depending skirt on said. grate.

e. stolser, a vertical member having a sphericai seat, a grate having a complementary spherical seat coacting with said first-named spherical seat for supporting said grateY and means coacting with said grate for circumferentially progressively tilting said grate on said spherical seat, comprising an eccentric rotative on said member and journalled in a depending skirt on said grate, said eccentric having an outer cylindrical surface the axis of which is inclined to the axis of said vertical member, and said outer cylindrical surface engaging the inside iace or" the wall of said skir 4. In an underfeed stoiier, a vertically extending fuel feed tube, having a spherical seat, a grate having a complementary spherical seat coactlng with said rst named spherical seat for supporting said grate, and means coacting with said grate for circumferentially progressively tilting said grate on said spherical seat'.

5. In a stoker, a member having a spherical seat, a grate having a complementary spherical seat coacting with said rst named spherical seat for supporting said grate, and means coacting with said grate for circumferentially progressively tilting said grate on said spherical seat, comprising an eccentric rotative on said member and journalled in a depending skirt on said grate, said eccentric having spaced radial ribs connecting with an annular ash conveying member located beneath said grate, and means for rotating said conveying member.

6. In a stolzer, a member having a spherical seat, a grate having a complementary spherical seat coacting with said rst named spherical seat for supporting said grate, and means coacting with said grate for circumferentially progressive- 1y tilting said grate on said spherical seat. comprising an eccentric rotative on said member and journalled in a depending skirt on said grate. said eccentric having spaced 'radial ribs connecting with' an annular ash conveying member located beneath said grate, and means for rotating said conveying member, said ,conveying member being surrounded by an outer housing having a portion terminating in a spherical surface concentric with said rst named spherical seat and the outer periphery of said grate having a spherical surface spaced inwardly from the spherical surface on said housing, whereby the progressive tilting of said grate facilitates passage oi ash through the space between the grate and the housing. l

7. In 'a Stoker, a member having a spherical seat, a grate having a complementary spherical seat coacting with said first named spherical seat for supporting said grate, and means coacting with said grate, for circumferentially progressively tilting said grate on said spherical seat, comprising an eccentric rotative on said member and journalled in a depending skirt on said grate, said eccentric having spaced radial ribs connecting with an annular ash conveying member located beneath said grate, and means for rotating said conveying member, said conveying member being surrounded by an outer housing having a portion terminating in a spherical surface concentric with said rst named spherical seat and the outer periphery of said grate having a spherical surface spaced inwardly from the spherical surface on said housing, whereby the progressive tilting of said grate facilitates passage of ash ing with 50 a depending skirt on said through the space between the grate and the' housing, the periphery ofthe conveying member and the inner wall of said housing being connected by an air seal so that combustion air with- 6 in the housing must pass between said ribs.

8. In a stoker, a member having a spherical seat, a grate having a complementary spherical seat coacting with said ilrst named spherical seat for supporting said grate, and means coacting. l0 with said grate for circumferentially progressively tilting -said grate on said spherical seat, comprising an eccentric 4rotative on said member and journalled in a depending skirt on said grate, said eccentric having Spacd radial ribs connectan annular ash conveying member located beneath said grate. and means for rotating said conveying member. said conveying member being Surrounded by an outer housing having a portion terminating in a spherical surface concentric with said ilrst named spherical seat and the outer periphery of said grate having a spherical surface spaced inwardly from the spherical i surface-on said housing, whereby the progressive tilting of said grate facilitates passage of ash through the space between the grate and the housing, the periphery of the conveying member and the inner wall of said housing being connected by an air seal so that combustion air within the housing must pass between said ribs, and A said conveying member having an 4annular baille portion around said ribs to shield the conveying member from the iiow of said combustion air.

9. In an underfeed stoker, 'a vertically extending fuel feed tube having a spherical seat at its upper end, a grate member resting upon and communicating with said tube and lhaving a complementary spherical seat coacting with' said first named seat, and means coacting with said grate for circumferentially progressively tilting said 40 grate on said spherical seat.

10. In an under feed stoker, avertically extending fuel feed tube having a spherical seat at itsv upper end, a grate member resting upon and comlmunicating with said tube and having a complementary spherical seat coacting with said first 4named seat, and means coacting with said grate or circumferentially progressively tilting said grate on said spherical seat, comprising an eccentric yrotative on said member and journalled in grate.

11. In an under feed stoker, a vertically extending fuel feed tube having a spherical seat at its upper end, a grate member resting upon and communicating with said tube and having a complementary spherical seat coacting with said iirst named seat, and meanscoacting with said grate for circumferentially progressively tilting said grate on said spherical seat, comprising an eccentric rotative on said member and journalled in a odepending skirt on said grate, said eccentric having an outer cylindrical surface, the axis of which is inclined. to the axis of said vertical member,

. and said outer cylindrical surface engaging the inside face of the wall of said skirt.

g5 12.` In an under feed stoker, a vertically extending fuel feed tube having a spherical seat at its upper end, an annular grate member supported uponand communicating with said tube and having a complementary spherical seat coacting with said rst named seat, an outer housing having a portion terminating in a spherical surface concentric with said flrst named spherical seat. the outer periphery of said grate having a spherical surface spaced inwardly from thel spherical surface on said housing. means for feeding fuel lsively tilting said ing said grate on said 5 through said tube to the grate, and means coacting with said grate for circumferentially progresgrate on said spherical seat whereby the fuel is agitated and the passage o'f the ashes through the space .between the grate and the housing is facilitated.

13. In an underfeed stoker, a vertically extending fuel feed tube having a spherical seat at its upper end. a grate member resting upon and communicating with said tube and having a complementary spherical seat coacting with said rst named seat, an eccentric rotatably mounted on said tube below said grate. said eccentric having an outer cylindrical surface the axis of which is inclined to the axis of said tube, a depending skirt on said grate journaled on said eccentric, and means operable to rotaie said eccentric whereby said grate moves with a circumferentially, progressive tiltingmovement.

' 14. In a stoker, a member having a spherical seat. a grate having a complementary 'spherical seat coacting with said rst named spherical seat for supporting said grate, and means coacting with said grate for circumferentially progressively tiltspherical seat, comprising an eccentric rotative on said member and journaled in a depending skirt on 'said gl'atefsaid eccentric having spaced radial ribs connecting with an annular ashrconveying member located beneath said grate, and means for rotating said conveying member, said conveying member being surrounded by an outer housing having a portion terminating in a spherical surface concentric with said rst named spherical seat and the outer periphery of said grate having a spherical surface spaced inwardly from the spherical surface on said housing, whereby the progressive tilting of said grate facilitates passage of ash through the space between the grate and the housing, the periphery of the conveying member and the inner wall of said housing` being connected by an air seal so that combustion air within the housing must pass between said ribs, and said conveying member having an annular bame portion around said ribs to shield the conveying member from the ow of said combustion air, and means for discharging ash from said conveying member.

l5. In a stoker, a vertical member having a spherical seat, a grate having a complementary spherical seat coacting with said A'ilrst named spherical seat for supporting said grate, means coacting with said grate for circumferentially progressively tilting said grate on said spherical seat,said grate having a frusto conical shaped peripheral portion, and awall above and opposed to said Vfrusto conical shaped peripheral portion, whereby there is crushing of fuel between these parts during all upward tilting of portions of said grate.

16. In a stoker, a stationary member, a second member having a cam surface whose axis is eccentric and inclined to the normal axis of the first member and rotatively mounted on said first member, la. grate, means supporting said grate over said second member in coacting relationship with said cam surface, and means for rotating said second member and thereby progressively tilting the periphery of said grate.

17. In a stoker, a stationary member. a cam rotatively mounted on said member and -having its axis inclined to the normal axis of said member, a grate, means for supporting 4said grate superimposed over and contacting with said cam, and means for rotating said eccentric and there- 75 A by circumferentially progressively tilt said grate. ment in said imaginary cone, said second. member 18. In a stoker or similar device, a grate havbeing rotatively mounted on mid. iin-st member ing ay frusto-conical surface, a stationary wall and coacting with said grate to tilt the same, and opposed to said surface, abearing for said grate, means for rotating said second member .and

s 5 and means for movingsaid grate on said bearing therefor progressively tilting the periphery ci said so that the axial center line of" the grate travels grate. 5 on the surface of an imaginary cone having its 20. In astoker or similar device, a grate having apex on thesame side of the base ofthe grate as a frusto-conical surface, a stationary wall opthe apex of said frusto-conical grate. posed to said surface, a bearing for said grate,

l0 19. Iny a stoker or similar device, a grate hav means for moving said grate on said bearing se ing a frusto conical surface, a wail opposed to said that the axial center line of the grate travels on l0 frusta-corneal surface, and means for moving said the surface of an imaginary cone having its apex grate so that its axial center line travels on the s on the same side of the base of the grate as the surface of an imaginary cone havlngits apex on apex or said frusta-conical grate, and said sta- 15 the same side of the base of the grate as the apex tionary wall being substantially coaxial with said of said frusto conical surface, comprising a -staimaginary cone, whereby relative movement ci? the 15 tionary member supporting said grate, a second grate to said wall will have a crushing eect upon. member having acam surface whose axis is eccenmaterial therebetween. tric and inclined to tiney normal axis of the rst 20 member, the Vaxis of said eccentric being an elel v JAMES GUNNEL liALOr. *20 

